package com.superatom.innerclasses;

interface Incrementable{
    void increment();
}

class Callee1 implements Incrementable{
    private int i = 0;
    public void increment() {
        i++;
        System.out.println(i);
    }
}

class MyIncrement{
    public void increment(){
        System.out.println("Other operation");
    }

    static void f(MyIncrement mi){
        mi.increment();
    }
}

class Callee2 extends MyIncrement{
    private int i = 0;
    public void increment(){
        super.increment();
        i++;
        System.out.println(i);
    }

    // 显示了接口与接口的实现是独立的，即使用者完全不知道Incrementable如何实现
    // 还有就是使用者不能直接调用接口实现类，而是通过接口调用
    private class Closure implements Incrementable{

        public void increment() {
            Callee2.this.increment();
        }
    }

    Incrementable getCallbackReference(){
        return new Closure();
    }
}

class Caller{
    private Incrementable callbackReference;
    Caller(Incrementable cbh){
        callbackReference = cbh;
    }

    void go(){
        callbackReference.increment();
    }
}


public class Callbacks {
    public static void main(String[] args){
        Callee1 c1 = new Callee1();
        Callee2 c2 = new Callee2();
        MyIncrement.f(c2);

        Caller caller1 = new Caller(c1);
        Caller caller2 = new Caller(c2.getCallbackReference());

        caller1.go();
        caller1.go();
        caller2.go();
        caller2.go();
    }
}
